arch/tile: improve trap handling a bit

We now respond to MEM_ERROR traps (e.g. an atomic instruction to
non-cacheable memory) with a SIGBUS.

We also no longer generate a console crash message if a user
process die due to a SIGTRAP.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

diff --git a/arch/tile/kernel/intvec_64.S b/arch/tile/kernel/intvec_64.S
index 709e2241e9aaf59fae72f26aac732e3f65397823..6a1ea82372d227be10dafdb5138c8ffc50e76d87 100644 (file)
--- a/arch/tile/kernel/intvec_64.S
+++ b/arch/tile/kernel/intvec_64.S
@@ -1186,7 +1186,7 @@ STD_ENTRY(fill_ra_stack)
 #define do_hardwall_trap bad_intr
 #endif
 
-       int_hand     INT_MEM_ERROR, MEM_ERROR, bad_intr
+       int_hand     INT_MEM_ERROR, MEM_ERROR, do_trap
        int_hand     INT_SINGLE_STEP_3, SINGLE_STEP_3, bad_intr
 #if CONFIG_KERNEL_PL == 2
        int_hand     INT_SINGLE_STEP_2, SINGLE_STEP_2, gx_singlestep_handle

diff --git a/arch/tile/kernel/traps.c b/arch/tile/kernel/traps.c
index 1e91fdac59ba700eb000fc001babb628f089576f..4c3305765360f47f688493228ef35440ea12ea37 100644 (file)
--- a/arch/tile/kernel/traps.c
+++ b/arch/tile/kernel/traps.c
@@ -199,7 +199,7 @@ void __kprobes do_trap(struct pt_regs *regs, int fault_num,
 {
        siginfo_t info = { 0 };
        int signo, code;
-       unsigned long address;
+       unsigned long address = 0;
        bundle_bits instr;
 
        /* Re-enable interrupts. */
@@ -222,6 +222,10 @@ void __kprobes do_trap(struct pt_regs *regs, int fault_num,
        }
 
        switch (fault_num) {
+       case INT_MEM_ERROR:
+               signo = SIGBUS;
+               code = BUS_OBJERR;
+               break;
        case INT_ILL:
                if (copy_from_user(&instr, (void __user *)regs->pc,
                                   sizeof(instr))) {
@@ -311,7 +315,8 @@ void __kprobes do_trap(struct pt_regs *regs, int fault_num,
        info.si_addr = (void __user *)address;
        if (signo == SIGILL)
                info.si_trapno = fault_num;
-       trace_unhandled_signal("trap", regs, address, signo);
+       if (signo != SIGTRAP)
+               trace_unhandled_signal("trap", regs, address, signo);
        force_sig_info(signo, &info, current);
 }